The invention relates to a laminating system for a web and in particular to a laminator having a loading system for a relatively wide lightweight web employing a support wall having a threading slot conforming to a complex feed path for the web.
So-called peel apart laminated films are known. These films generally comprise a lamination of a substrate, a disposable peel sheet layer and a multicomponent, intermediate radiation sensitive, adhesive image forming layer. The film is selectively exposed to radiant energy to produce an image in the image forming layer. The substrate and the adhered image forming layer are thereafter separated from the peel sheet, and the image is retained in the image forming layer adhered to the substrate. In order to protect the image, the substrate is coated with a protective film.
Thermographic film of the type used for x-ray imaging is produced in relatively large sheets measuring up to 8.times.10 inches. Wet processing is becoming a less desirable image forming expedient, because it is complex and difficult to successfully implement on a regular basis. Also, wet processing produces waste products which create environmental concerns. Accordingly, dry processing techniques are preferred. One known method of dry processing calls for thermally applying a protective coating after the image has been developed. The method involves bringing the image forming layer adhered to the substrate into intimate contact with a web carrying a thermosensitive layer, and heating the web to cause the thermosensitive layer to adhere to the image forming layer and thereafter removing the web from the substrate.
The laminating apparatus adapted to carry out such a process has a feed path for the substrate and a feed path for the web. The web feed path is tortuous and it is difficult for non-technical personnel to handle and load the web. Thus, it is important and desirable to provide an apparatus which is simple to load. This is especially true in clinical applications where personnel responsible for using the apparatus on a regular basis may not have special mechanical training.
Self threading systems are not an available expedient because the web is too thin and unpredictable in its behavior. Also, the web is wider than the film, e.g., 18 inches. Thus, it is difficult to direct such a wide web through a tortuous path.